A Study of the Genetic Adaptations in Enterobacter sakazakii

Enterobacter sakazakii a Gram negative, rod-shaped bacterium is the causative agent of a severe form of neonatal meningitis causing a 40-80% mortality rate. Case studies have established dry powdered infant feeding formula to be the source and vehicle of infection. Since the infection is contracted via ingestion of contaminated formula, it is vital to understand the factors or adaptive mechanisms that allow the organismís survival in the acidic environment in the stomach. It has been shown that the organism can survive at pH 3.5 from a stationary phase of growth, an important conclusion since the normal pH in an infantís stomach is around 3.5. In addition to determining the microbeís antibiotic resistance and growth curve, an electroporation protocol has been optimized for the organism. Currently, transposon mutagenesis is being carried out to create a library of E. sakazakii mutants and then screen for those genetic mutations that abrogate the organismís osmotolerance and acid adaptivity.